ES2673970T3 - Method and apparatus for monitoring and processing component carriers - Google Patents

Abstract

A method implemented by a wireless transmission / reception unit, WTRU, the method comprising: transmitting (410) an indication of a WTRU bandwidth aggregation capability; receiving (415) a radio resource control connection reconfiguration message, RRC, in which the RRC connection reconfiguration message configures the WTRU to support at least one additional component carrier, and the message The reconfiguration of the RRC connection does not activate the at least one additional component carrier; receiving (425) a control element, CE, from the media access control, MAC, in which the MAC CE indicates that the at least one additional component carrier must be activated; activate (425) the supervision and processing of at least one additional component carrier based on the reception of the MAC CE.

Description

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DESCRIPTION

Method and apparatus for monitoring and processing component carriers Technical field

This application refers to wireless communications.

Background

A key feature of advanced long-term evolution (LTE-A - Long Term Evolution - Advanced) is a higher data rate. This is supported by allowing a wireless transmission / reception unit (WTRU) to receive and transmit data simultaneously on multiple LTE component carriers, both uplink and downlink. This is known as carrier aggregation.

The reception and transmission in multiple carriers significantly increases the power consumption of the WTRU. It is known that the power consumption of the analog interface (which counts as a significant fraction of the total power consumption in the WTRU) is linearly proportional to the bandwidth or a plurality of basic frequency blocks (i.e., component carriers) that They are added. Activating and deactivating additional component carriers on demand and quickly is critical to saving WTRU resources (for example, hybrid automatic repeat request processing (HARQ) (including channel quality (CQI - Channel Quality Indicator (in English) and communication of the sounding reference signal (SRS), occupation of the buffer and management of the buffer (for example, communication of the report of the memory status intermediate (BSR - Buffer Status Report, in English) and programming processing), and provide savings in energy consumption.

The "Issues on Carrier Aggregation for Advanced E-UTRA" document, Draft 3GPP, R1-083528, describes problems related to carrier aggregation.

The document "Ll control signaling with carrier aggregation in LTE-Advanced", Draft 3GPP, R1-083730, describes problems related to carrier aggregation.

Compendium

A method and a WTRU are provided according to the independent claims.

A method and apparatus describing bandwidth aggregation by monitoring and describing are described.

simultaneously processing a number of contiguous or non-contiguous component carriers, simultaneously, in the downlink. A WTRU can be configured by an evolved Node B (eNodeB - Evolved NodeB, in English) to support additional component carriers. An additional preconfigured component carrier can be used. Various methods for activating and deactivating the additional component carrier are also described.

Brief description of the drawings

A more detailed understanding can be obtained from the following description, given by way of example together with the accompanying drawings, in which:

Figure 1 shows a wireless communication system that includes an eNodeB and a WTRU; Figure 2 is a block diagram of the eNodeB of Figure 1;

Figure 3 is a block diagram of the WTRU of Figure 1; Y

Figures 4 and 5 show procedures for monitoring and processing of component carriers. Detailed description

When mentioned below, the terminology "wireless transmission / reception unit (WTRU)" includes, but is not limited to, a user equipment (UE), a mobile station, a fixed subscriber unit or mobile, a locator, a cell phone, a personal digital assistant (PDA), a computer, or any other type of user device capable of operating in a wireless environment.

When mentioned below, the terminology "Evolved Node B (eNodeB)" includes, but is not limited to, a base station, a site controller, an access point (AP - Access Point, in English) or any other type of an interface device capable of operating in a wireless environment.

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Figure 1 shows a wireless communication system 100 that includes an eNodeB 105 and a WTRU 110. The eNodeB 105 is configured to transmit a reconfiguration message of the radio resource control connection (RRC). 115 to WTRU 110.

Various methods and apparatus for activating or deactivating the reception or transmission in the different carriers in an advanced LTE system employing carrier aggregation are described.

Transition to connected mode

In an inactive mode, the WTRU 110 monitors and processes only a single component carrier. Inactive mode procedures, such as obtaining system information (SI - System Information, in English) and monitoring the location indication (PI - Paging Indication, in English) are transparent to the capacity of multiple carriers of the system. WTRU 110. Schemes such as cell selection and cell reselection may remain the same with or without carrier aggregation capacity (hereinafter referred to as bandwidth aggregation), or they may consider the aggregation capacity of bandwidths. the infrastructure, (eNodeB 105), as an entry to the system selection. However, when the WTRU 110 enters a connected RRC mode, (typically through a RRC connection request), the WTRU 110 informs the network of the WTRU's capacity in terms of bandwidth aggregation.

The bandwidth aggregation capability of the WTRU can be defined as the number of simultaneous non-contiguous component carriers that can be monitored and processed simultaneously on the downlink for each band. An alternative metric may be the number of radio frequency (RF) receivers, (handling different receivers, non-contiguous carriers), and greater bandwidth of each receiver. Consider an example in which there are five component carriers: carriers 1 and 2 are contiguous with each other but not carriers 3, 4 and 5, and carriers 3, 4 and 5 are contiguous.

The bandwidth aggregation capability of the WTRU can also be defined as the number of simultaneous contiguous carriers that can be monitored and processed simultaneously on the downlink for each band.

The WTRU bandwidth aggregation capability can also be defined as the largest bandwidth supported by contiguous carriers added, not only the number of carriers, but also the bandwidth.

WTRU bandwidth aggregation capability can also be defined as the largest total bandwidth of aggregate carriers (contiguous or not).

The bandwidth aggregation capability of the WTRU can also be defined as the largest bandwidth supported by a single carrier (in line with the current WTRU capacity of LTE).

RRC configuration of component carriers

After the WTRU informs the network of the bandwidth capacity of the WTRU in the RRC connection procedure, an aggregation of bandwidths compatible with the eNodeB can configure the WTRU to support additional component carriers, (i.e. , additional preconfigured component carriers). This can be accomplished with an RRC connection reconfiguration message that transmits information that allows the WTRU to establish the supervision, (concessions and assignments), of one or more additional downlink and / or uplink carriers. The information included in the RRC connection reconfiguration message may include the cell identity (ID), the carrier's center frequency, the carrier bandwidth, the carrier address (uplink or downlink) and other information necessary to timely configure the activation and synchronization of the preconfigured additional component carriers.

An RRC connection reconfiguration message may be sufficient to configure more than one component carrier by stacking the information described above for all additional preconfigured component carriers.

Receiving only the RRC connection reconfiguration message cannot activate monitoring and processing of additional component carriers immediately or after a delay. In this case, only an explicit or implicit activation order as described below would allow the WTRU to begin monitoring and processing additional carriers. Alternatively, the RRC connection reconfiguration message may contain a field indicating whether monitoring and processing should or should not be initiated after the reconfiguration procedure has been successfully completed. This can be useful for verifying in the configuration that the preconfigured additional component carriers are operational. Alternatively, the reception of the RRC connection reconfiguration message activates the monitoring and processing of the additional component carriers immediately or after a delay.

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The RRC connection reconfiguration message may contain additional information that would allow the WTRU to configure additional component bearers controlled by another eNodeB, such as timing advance and other synchronization related information.

The RRC connection reconfiguration message may provide a specific cellular radio network identifier (C-RNTI) for each additional component carrier.

The RRC connection reconfiguration message can, for greater efficiency, assign each pre-configured additional component carrier a combination of bits up to the maximum number of simultaneous additional component carriers that can be supported, so that activation can be referred to or deactivation of an individual component carrier using this assigned bit combination.

Mechanisms for activating or deactivating additional preconfigured component carriers

MAC control elements

Activation or deactivation of a preconfigured additional carrier or a predefined subset of preconfigured additional carriers can occur during the reception of a control element (CE - Control Element, in English) for medium access control (MAC - Medium Access Control, in English). Activation or deactivation can take effect after a predefined delay, (fixed or configurable by upper layer signaling) or immediately after receipt of the mAc CE. This would be implemented by a new type of MAC CE, called control element Activation_of_CE_of_MAC.

The ECA_CE_Activation control element may contain a bit combination field to indicate which preconfigured carrier is being activated or deactivated. Alternatively, the carrier that is activated or deactivated can be indicated by the value of the C-RNTI used for the transmission of the MAC PDU containing the MAC control element. An ECM_Activation_ control element can activate or deactivate multiple carriers at the same time by adding bit combinations or transmitting multiple MAC PDUs using a different C-RNTI.

The indication of whether the order corresponds to activation or deactivation can be done by setting a bit, or it may be implicit based on the current activation or deactivation status of the carrier. Alternatively, it may be based on the carrier in which the MAC PDU was received. For example, if the MAC CE was contained in a MAC PDU received on a given carrier (for example, an "anchor carrier" or a "service cell"), then it is understood that the order is for the activation of the carrier indicated in the MAC CE. If the MAC CE was contained in a MAC PDU received on a carrier, (possibly without explicit indication of a carrier within the MAC CE itself), then it is understood that the order is a deactivation for the carrier from which it was received. the MAC PDU, or, alternatively, a deactivation for a predefined set of carriers.

Another alternative is that all ECM_Activations are always received on a specific carrier (for example, the carrier corresponding to the service cell).

Activation on demand

The reception of a physical downlink control channel (PDCCH) in a specific carrier (such as an "anchor carrier") with a new format of downlink control information (DCI - Downlink Control Information (in English) or a modified DCI format for advanced LTE) may indicate to the WTRU that transmission to or reception from, an uplink carrier (PUSCH - Physical Uplink Shared CHannel) or link Additional downlink (PDSCH - Physical Downlink Shared CHannel), (or a predefined subset of pre-configured uplink or downlink carriers), will be performed in X subframes. (To start monitoring the PDCCH on a new carrier, some subframes of timeout are necessary.) The delay allows the WTRU analog interface to be configured on the new carrier, which includes a phase-locked loop (PLL) and automatic gain control (AGC - Automatic Gain) control, in English) establish time and frequency synchronization. The new DCI format contains a field to assign (map) activation with the preconfigured carrier as explained above. This allows the WTRU to only monitor the PDcCh from a single carrier, (for example, a special carrier called "anchor carrier" or the carrier corresponding to the service cell), and consequent battery savings. The anchor carrier indication may be for a single concession or assignment in the additional component carrier. In this case, HARQ feedback corresponding to the concession or assignment can also be delayed (with respect to PDCCH transmission) compared to existing systems. Alternatively, the anchor carrier indication may indicate to the WTRU that it should begin monitoring the PDCCH in the additional component carrier or in the subset of component carriers, until this carrier (or these carriers) is deactivated or deactivated.

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The PDCCH received with a new DCI format (or modified DCI format for advanced LTE) on a carrier, (for example, an "anchor carrier"), can provide a time-delayed allocation (physical resource blocks (PRB - Physical Resource Block, in English, modulation and coding sets (MCS) and others in a preconfigured additional component carrier. The delay is based on the WTRU's ability to tune in and synchronize a preconfigured component carrier. This delay can be fixed or variable based on the capacity of the WTRU. The time-delayed allocation is already used for the uplink assignment - a delay of four subframes. However, this method allows the WTRU to know the possibility of a more advanced next uplink transmission compared to the existing system. Such advanced knowledge can be useful for uplink programming decisions. The same approach can be used for a preconfigured additional component carrier. This has the advantage that additional preconfigured component carriers are activated on demand by allocating resources in advance.

Implicit activation

The implicit activation of one or more carriers can take place when the volume of traffic received on the downlink (measured at the physical layer (PHY)) of the MAC radio link control (RLC), or from Packet Data Convergence Protocol (PDCP), within a predetermined or configured amount of time, is greater than a predetermined or configured threshold.There may be several defined thresholds, each corresponding to a carrier particular to activate, for example, carrier C1 can be activated when traffic volume is greater than V1, and carrier C2 can be activated when traffic volume is greater than V2, and the like.

The implicit activation of one or more carriers can also take place when the WTRU initiates the transmission (in the random access channel (RACH - Random Access CHannel), in the physical uplink control channel (PUCCH - Physical Uplink CHannel control, in English) or in the physical uplink shared channel (PUSCH), on a certain uplink bearer that is associated with the downlink bearer to activate it.This association can be predefined or provided to the WTRU by signaling of RRC, (system information or dedicated signaling).

When a downlink carrier is activated, the WTRU initiates reception in the PDCCH configured for this carrier (if a PDCCH is defined for each carrier) and the transmission in the PUCCH is configured so that this carrier transmits the feedback information.

Implicit Deactivation

Implicit deactivation can be carried out based on a specific inactivity timer for the activity of the additional component carrier. For example, only the anchor carrier is active during a web browsing session. If a download is started, the assignment of the PRBs on the additional component carrier pre-configured for this WTRU begins. Once the download is complete, the network stops allocating resources to the additional component carrier preconfigured for the WTRU. After the expiration of a certain inactivity timer (specific for the preconfigured carrier), the WTRu stops monitoring the PDCCH (that is, a dedicated PDCCH for each carrier) and cancels the interface radio resources assigned to this carrier. Alternatively, the WTRU may stop the monitoring of a carrier's PDCCH after the expiration of a timing alignment timer (or other timer) specifically defined for this carrier. Said timing alignment timer may be reset based on the reception of a timing alignment MAC control element from a MAC PDU received in the carrier.

In case of activation on demand and a shared control channel on the anchor carrier, the WTRU can cancel the interface resources assigned to a preconfigured additional component carrier as soon as the time-delayed allocation for this carrier has not been received. . The WTRu may determine that it is more optimal to wait for some consecutive subframes without assigning additional preconfigured component carriers before canceling the interface resources associated with these carriers.

Implicit deactivation can also be based on radio conditions. As an example, if the conditions of a carrier's channel remain below a certain minimum threshold for a period of time, the radio resources of the interface can be deallocated.

Explicit deactivation order in the PDCCH

Explicit deactivation can be carried out by sending a specific deactivation order for the component carrier so that the WTRU no longer needs to monitor the PDCCH, (dedicated PDCCH for each carrier). The order can be sent using a PDCCH with a new DCI format in the anchor carrier for the dedicated channel. Alternatively, the deactivation order used by the PDCCH can only be sent to the additional preconfigured component carrier.

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Activation or deactivation in DRX connected mode

The configuration of the MAC DRX can remain the same as carrier aggregation. The duration and DRX cycle applies to configured carriers (for example, to an "anchor carrier" or service cell), as well as to additional preconfigured components activated components ("resource carriers").

A DRX idle timer that runs on the WTRU can be started or restarted if the PDCCH is received through an additional preconfigured component carrier activated for a new transmission.

The DRX idle timer can also be started or restarted if a scheduled concession is received for a preconfigured additional component carrier activated for a new transmission.

Alternatively, the MAC DRX configuration may have a specific DRX inactivity timer for each of the additional preconfigured component carriers. The DRX inactivity timer associated with a carrier will start or restart when a PDCCH assignment is received on this carrier. This would allow the WTRU to effectively deactivate these preconfigured carriers until the next duration cycle, while the anchor carrier remains in active time.

The logic described above for the DRX inactivity timer can also be applied to other DRX timers, such as the duration timer and the DRX retransmission timer.

Figure 2 is a block diagram of eNodeB 105 of Figure 1. The eNodeB 105 includes an antenna 205, a receiver 210, a processor 215 and a transmitter 220. The receiver 210 is configured to receive a signal indicating a capacity of WTRU 110 bandwidth aggregation. The transmitter 220 is configured to transmit a reconfiguration message of the RRC connection to the WTRU 110.

Figure 3 is a block diagram of the WTRU 110 of Figure 1. The WTRU 110 includes an antenna 305, a receiver 310, a processor 315, a transmitter 320 and a discontinuous reception inactivity timer (DRX) 325.

The WTRU 110 monitors and processes the component carriers. The receiver 310 in the WTRU 110 is configured to monitor and process a single component carrier. The transmitter 320 in the WTRU 110 is configured to transmit a signal indicating a bandwidth aggregation capability of the WTRU 110. The receiver 310 is further configured to receive a reconfiguration message of the RRC connection. The processor 315 in the WTRU 110 is configured to establish the monitoring and processing, at least, of a preconfigured additional component carrier.

Receiver 310 may also be configured to receive a MAC CE, and processor 315 may be configured to enable or disable the preconfigured additional component carrier.

The preconfigured additional component carrier can be activated or deactivated immediately in response to the reception of the MAC CE, or it can be activated or deactivated after a predefined delay. The preconfigured additional component carrier may be an uplink carrier or a downlink carrier.

The WTRU 110 can monitor and process the single component carrier while in idle mode.

In one example, the bandwidth aggregation capability may indicate a number of simultaneous non-contiguous component carriers that can be monitored and processed simultaneously on the downlink for each band.

In another example, the bandwidth aggregation capability may indicate a number of RF receivers and the highest bandwidth of each receiver.

In yet another example, the bandwidth aggregation capability may indicate a number of contiguous simultaneous carriers that can be monitored and processed simultaneously on the downlink for each band.

In another example, the aggregation capacity of bandwidths may indicate the greater bandwidth supported of the contiguous carriers added.

In another example, the aggregation capacity of bandwidths may indicate the greater total bandwidth of aggregate carriers.

In another example, the aggregation capacity of bandwidths may indicate the greater bandwidth supported by each single carrier.

The bandwidth aggregation capacity may indicate more than one of the examples described above.

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In another scenario, receiver 310 may be configured to receive a PDCCH on a specific carrier with a DCI format indicating that transmission to, or reception from, a preconfigured uplink or additional downlink carrier will take place in a certain number of subframes. Processor 315 can be configured to monitor and process the preconfigured carrier.

Figure 4 shows a procedure 400 for monitoring and processing component carriers. In step 405, a WTRU monitors and processes a single component carrier. In step 410, the WTRU transmits a signal indicating a WTRU bandwidth aggregation capability. In step 415, the WTRU receives a reconfiguration message of the RRC connection. In step 420, the WTRU is configured to monitor and process at least one additional preconfigured component carrier. In step 425, the WTRU activates or deactivates the preconfigured additional component carrier in response to the reception of a MAC CE.

Figure 5 shows a procedure 500 for monitoring and processing of component carriers. In step 505, a WTRU monitors and processes a single component carrier. In step 510, the WTRU receives a PDCCH on a specific carrier with a DCI format indicating that transmission to, or reception from, a preconfigured uplink or additional downlink carrier will take place in a certain number of subframes. . In step 515, the WTRU is configured to monitor and process the preconfigured carrier.

Although features and elements have been described above in particular combinations, each feature or element may be used alone, without the other features and elements or in various combinations with or without other features and elements. The methods or flowcharts provided herein may be implemented in a computer program, software or firmware incorporated in a computer-readable storage medium for execution by a general purpose computer or a processor. Examples of computer readable storage media include a read-only memory (ROM), a random access memory (RAM), a register, a cache, memory devices semiconductor memory, magnetic media such as internal hard drives and removable drives, magneto-optical media, and optical media such as CD-ROM discs and digital versatile discs (DVD - Digital Versatile Disks).

Suitable processors include, by way of example, a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, application specific integrated circuits (ASIC), application specific standard products (ASSP), circuits of matrices of programmable doors by field (FPGA - Field Programmable Gate Arrays, in English), any other type of integrated circuit (IC - Integrated Circuit) and / or a state machine.

A processor in association with software can be used to implement a radio frequency transceiver for use in a wireless reception transmission unit (WTRU), a user equipment (UE), a terminal, a base station, a management entity of the mobility (MME - Mobility Management Entity, in English) or an evolved packet core (EPC - Evolved Packet Core, in English), or any host. The WTRU can be used together with modules, implemented in hardware and / or software that include a software-defined radio (SDR - Software Defined Radio, in English) and other components such as a camera, a camcorder module, a videophone , a speaker, a vibration device, a speaker, a microphone, a television transceiver, a hands-free headset, a keyboard, a Bluetooth® module, a frequency modulated radio (FM) unit, a communication module near field (NFC), a liquid crystal display unit (LCD), an organic light emitting diode display unit (OLED) - Organic Light-Emitting Diode, in English), a digital music player, a media player, a video player, an Internet browser and / or any wireless local area network (WLAN) or ultra-wideband (UWB - Ultra Wid) module e Band, in English).

Claims (22)

5 10 fifteen twenty 25 30 35 40 Four. Five 1. A method implemented by a wireless transmission / reception unit, WTRU, comprising the method: transmitting (410) an indication of a bandwidth aggregation capability of the WTRU; receiving (415) a radio resource control connection reconfiguration message, RRC, in which the RRC connection reconfiguration message configures the WTRU to support at least one additional component carrier, and the message The reconfiguration of the RRC connection does not activate the at least one additional component carrier; receiving (425) a control element, CE, from the media access control, MAC, in which the MAC CE indicates that the at least one additional component carrier must be activated; activate (425) the supervision and processing of at least one additional component carrier based on the reception of the MAC CE. 2. The method according to claim 1, wherein: activating the supervision and processing of the at least one additional component carrier comprises activating the supervision and processing of a physical downlink control channel, PDCCH, associated with the at least one additional component carrier. 3. The method according to claim 1 or 2, wherein the MAC CE comprises a bit combination field that is indicative of which component carrier is to be activated. 4. The method according to claim 3, wherein the bit combination field indicates that multiple component carriers must be activated. 5. The method according to claim 1, wherein a subsequent MAC CE that is received by the WTRU comprises a bit combination field indicating which component carrier should be deactivated. 6. The method according to claim 2, wherein the WTRU ceases to monitor the PDCCH associated with the at least one additional component carrier upon expiration of an inactivity timer for the at least one carrier. additional component 7. The method according to claim 6, wherein a respective inactivity timer is maintained for each of a plurality of additional component carriers configured for use by the WTRU. 8. The method according to claim 1, wherein the RRC connection reconfiguration message comprises a cell identity and a carrier frequency for the at least one additional component carrier. 9. The method according to claim 1, wherein the indication of bandwidth aggregation capability comprises an indication of a number of contiguous component carriers that the WTRU can be configured to simultaneously monitor the link falling. 10. The method according to claim 1, wherein the indication of bandwidth aggregation capability comprises an indication of a maximum aggregate bandwidth supported by the WTRU. 11. The method according to claim 1, wherein the at least one additional component carrier comprises at least one of a downlink component carrier or an uplink component carrier. 12. A wireless transmission / reception unit (110), WTRU, comprising: means for transmitting an indication of a WTRU bandwidth aggregation capability; means for receiving a reconfiguration message of the radio resource control connection, RRC; wherein the RRC connection reconfiguration message configures the WTRU to support at least one additional component carrier and the RRC connection reconfiguration message does not activate the at least one additional component carrier; means for receiving a control element, CE, of the media access control, MAC, in which the MAC CE indicates that the at least one additional component carrier must be activated; Y 5 10 fifteen twenty 25 means for activating the supervision and processing of the at least one additional component carrier based on the reception of the MAC CE. 13. The WTRU according to claim 12, wherein the means for activating the monitoring and processing of the at least one additional component carrier are configured to activate the monitoring and processing of a physical control channel downlink, PDCCH, associated, at least with an additional component carrier. 14. The WTRU according to claim 12 or 13, wherein the MAC CE comprises a bit combination field that is indicative of which component carrier is to be activated. 15. The WTRU according to claim 14, wherein the bit combination field indicates that multiple component carriers are to be activated. 16. The WTRU according to claim 12, wherein a subsequent MAC CE that is received by the WTRU comprises a bit combination field indicating which component carrier should be deactivated. 17. The WTRU according to claim 13, wherein the WTRU is configured to stop monitoring of the PDCCH associated with the at least one additional component carrier upon expiration of an inactivity timer for the at least one, additional component carrier. 18. The WTRU according to claim 17, wherein a respective inactivity timer is maintained for each of a plurality of additional component carriers configured for use by the WTRU. 19. The WTRU according to claim 12, wherein the RRC connection reconfiguration message comprises a cell identity and a carrier frequency for the at least one additional component carrier. 20. The WTRU according to claim 12, wherein the indication of bandwidth aggregation capability comprises an indication of a number of contiguous component carriers that the WTRU can be configured to simultaneously monitor the link falling. 21. The WTRU according to claim 12, wherein the indication of bandwidth aggregation capability comprises an indication of a maximum aggregate bandwidth supported by the WTRU. 22. The WTRU according to claim 12, wherein the at least one additional component carrier comprises at least one of a downlink component carrier or an uplink component carrier.